Railway signaling system.



A. A. ARMSTRONG &'G. M. RIVES.

RAILWAY SIGNALING SYSTEM.

APPLICATION FILED APR. 30. 1914. RENEWED JAN. 24.1917.

Patented Aug. 14,1917.

4 SHEETS-SHEET Wit woes N A. A. ARMSTRONG & G. M. RIVES.

RAILWAY SIGNALING, SYSTEM. APPLICATION FILED APR-30, 1914. RENEWED JAN. 24.1917.

36, 97, Patented Au 11,1917.

4 SHEETSSHEET 2.

ag-W;

A. A. ARMSTRONG II G. M. HIV-ES.-

RAILWAY SIGNALING SYSTEM.

APPLICATION FILED APR. 30. 1.914. RENEWED IAN. 24. um.

Patented Au 14; 1917.

4 SHEETSSHEE1'3.

EINII. NIVLLL A. A. ARMSTRONG & G. M. RIVE-S.

RAILWAY SIGNALING SYSTEM.

, APPLICATION FILED APR-30.1914- RENEWED JAN. 24.1917. 1,236,897.

Patented Aug." 14, 1917;

I 4 SHEETSSHET 4.

mum m UNITED srarns PATENT OFFICE.

ALTON ALVIN ARMSTRONG, OF WATERTOl/VN, SOUTH DAKOTA, AND GEORGE MASON BIVES, OF LEAVENW'ORTI-I, KANSAS.

RAILWAY SIGNALING SYSTEM.

Application filed. April 30, 1914, Serial No. 835,549.

To all whom it may concern:

Be it known that we, ALTON A. ARM- s'ruoxc and Gnonen M. Rivns, citizens of the United States, residing at lVatertown, in the county of Codington and State of South Dakota, and Leavenworth, county of Leavenworth, State of Kansas, respectively, have invented certain new and useful Improvements in Railway Signaling Systems, of which the following is a specification, reference being had therein to the accompanying drawing.

Our invention relates to railway signaling systems, and has for its object the production of a system in which the maximum of safety and the minimum of complication shall be characteristic features. In order to attain the first part of our object we design track circuits, wayside signals, and engine cab devices so as to depend as little upon the human agency as possible. We find it expedient, however, to give the human agency primary control, subject to such automatic supervision (if we may so employ this term) that in case of any failure on the part of the human agent, abnormal conditions will inevitably and automatically accomplish without loss of time what the human agent should have done.

In brief but more specific explanation of the means we employ, it may be stated that the system is divided into three parts, that is, track circuits, wayside signals such as semaphores, and cab signals and controlling devices. The track circuits are so arranged that when a car or train enters a block, it is given possession of that block under normal conditions until a predetermined point is reached. when and where an automatic reversal of current furnishes a check on the engine drivers movements, and if normal also gives him a safety signal; but if the train enters a block when the block ahead is occupied, the engineer will immediately receive cautionary signals both from the way side and in his cab, the observance of which by cautionary running will leave him still in control of his train, but the disregard of which bv running too fast, or running past a danger signal. will immediately stop his train and disable his controlling mechanism, so that in order to start it again a positive act must be performed either by himself or by an inspector, and in addition thereto an automatic record Patented Aug. 14, 1917.

Renewed January 24, 1917. Serial No. 144,314.

made of the occurrence; and finally,'if a train enters a block which is already occupied, it will be stopped without any alternative whatever on the part of the driver.

In order to avoid complication, we do not employ track circuit closers, but instead make use of a principle which we have discovered for ourselves and believe to be thoroughly reliable, that is the drop in potential between front and rear trucks of a vehicle or between the front and rear trucks of the end cars of a train, where a source of potential is normally bridged across the rails of a block section. The existence of such a drop has been known before, but so far as we are aware, it has not been utilized and we shall therefore claim this feature as well as some others involved in our system both broadly and specifically in terms of the embodiment hereinafter illustrated and described.

Our invention is illustrated in the accompanying drawings in which:

Figure l is a diagram of three successive block sections equipped with the track circuit used in, our system.

Fig. 2 is a continuation of Fig. 1, showing the circuits of the three next succeeding blocks. Fig. 3 is a diagram of the cab circuit used in our system.

Fig. 4 is a diagram showing a slight modification of the circuits of the relays PR and R in Fig. 3.

Referring to Figs. 1 and 2, A, B, C, D, E and F are successive block sections, the rails of each section being insulated from those of the adjoining sections by suitable insulated joints 1. The arrangement of the track circuit is the same in each block section, the several sections being shown to illustrate their relation to each other and the different circuit conditions produced by the presence of a car therein. As the circuits in all the sections are identical, the description of one, for example B, will suffice. The battery 17 is connected to the track rails 56 and at 11 and 13 respectively, through a pole changer 21 and the windings of a polarized relay 22 It will be noted that the battery supply circuit is connected at opposite ends of the block section and diagonally of the track rails thus causing a flow of current through both rails W h ril b are connected through the trucks of a car, the wheels of each truck 12 or 12', forming a conductor of negligible resistance across the rails. V The pole changer 21 is operated by a solenoid 20 energized by current from battery 18 over various circuit paths to be described further on. Relay 21 is a potential or high wound relay having an armature 31" with two back contacts e11 and 42 The relay 23" is a current or low wound relay having an armature 32 with a front and back contact 37 and 38 respectively. The high resistance relay 21 is connected across the rails at 4:3" and 14' while the current relay 23 is connected to the ends 52 and 53 of a break in the rail 55 so that it is in series with the circuit of rail 55. Relay 30 and the polarized relay 25 are both potential or high wound relays, connected across the rails at 15 16 and 17 -ft8". The relays 30 and 25 jointly, control the semaphore 57 The structural details of the apparatus thus generally described are well known in the art and are therefore not pointed out in particular.

Proceeding with the circuit arrangement, the'track battery 17" has its poles 1 and 2 connected to the fixed contact 16 anc 3 5 respectively of the pole changer 21 The arms 15 and l are mechanically connected, for operation with the core 19 of the sole noid 20. Arm 15 of the pole changer is directly connected to the rail 56 at 13 and arm a is connected through the conductor 5 the windings of polarized relay 22 and conductor 10 to the rail 55 One terminal of the solenoid 20 is connected to the battery 18*, while the other terminal is connected in multiple to the normally open contact 31* of polarized relay 22 front contact 37 of low resistance relay 23 and the armature 31 of the high wound relay 24 of the next succeeding block section. The other side of battery 18 is connected in multiple to the armature 32 of relay 23 and the back contact 11 of relay 21 in the next suc ceeding block section. The connection of battery 18 is further extended, under certain conditions, from armature 32 to ar1na ture 31" by the circuit connection between back contacts 4 :2 and 38. he armature 31" of relay 2-1" is permanently connected to armature 33" of polarized relay 22 The circuit connections for solenoid 20, just described, put it under the control in common of both the relay 23 of its own block section and the relay 24 of the next succeeding block section, and under the joint control of relays 2& 23 and 22. The element 36" is an insulated rest for the armature 33 of relay The semaphore motor M' operates to hold the semaphore in clear position when its circuit is closed through the battery 31 The controlling circuit of the semaphore operating inotcr, includes in series, the armature 29 and contact 26 of relay 30 and the armature 28 and contact 27 of polarized relay 25 The polarized relay 25" is so connectedto the track rails 55 and 56 that its armature will assume the position shown when-the rail 56" is positive and the rail 55 negative. All the apparatus and circuits in block section B are shown in the normal or clear condition, 'a'. 6., when both the block sections B and the next succeeding one C are clear.

Referring to Fig. 3, which shows the cab circuit and apparatus, current is taken from the rails into the cab through the trucks 12 and 12. The primary portion of the cab circuit is protected by the inductance coil R connected in series therein to retard the flow of any alternating current, and the condenser c of suflicient capacity to shunt out any alternating current passed by the coil R. Various other protective devices well known in the art, may be provided, such as lighting arresters and fuses. Relay R and a polarized relay PR are connected in series in the primary cab circuit. This circuit may be traced as follows: truck 12, wire 108, coil R, wire 103, relay R wire 10 1, windings of polarized relay PR, wire 105 to truck 12. The relay R is provided with two armatures 120 and 161, the armature 120 being quick acting while armature 161 is rendered slow acting, in any well known manner, so as not to disengage its contact 12?) upon momentary deenergization of the relay magnet when the car passes over the insulated joints of the track rails. Included in one of the secondary or local circuits of the cab, are relays R R and R Relay R is provided with two armatures, a quick acting armature 119 and a slow acting armature 160, the armature 160 being provided with adjustable retarding means, not shown, so that it may be set to remain in engagement with its contact 129 for a predetermined time after de'e'nergization of the relay magnet. The armature 119 controls a locking circuit for its relay through contact 139. Relay R is provided with a slow acting armature 162 which, through contact 115, controls the initial energizing circuit of relay R. Relay R is connected in the circuit of battery 18 and is provided with an armature 121 controlling'the circuits of the red and green signal lamps. The armature 106 of the polarized relay PR is connected. to the battery 18 through the winding of relay ltl The armature 106 is provided with contacts 126 and 127 on each side thereof and the windings of the relay magnets are so connected to the trucks 12 and 12 that when truck 12 is positive and 12 negative the armature will engage contact 127 and when the polarity of the trucks is reversed the armature will engage contact 126. The slow acting armature 160 and 161 of relays R and R respectively, jointly control a secondary or local circuit operating the valve holding magnet MT and a recorder R0. The valve holding magnet is in the form of a solenoid and operates to hold the valve of the train line closed as long as current trav erses its winding. Connected with the core of the valve holding magnet is bridging contact 152 adapted, upon deonergization of the magnet, to bridge the contacts 123 and 12 1-. The recorder RC comprises the magnet 141 controlling a recording needle 1%2 adapted, when released by the magnet to be retracted by a suitable retractile spring and perforate a moving dial or tape 11%, the tape 1 1s being fed by suitable feed means 14. .8 operated by a clock train, all in a well known manner. The normally closed contact 14:6 operated by a push button 117 is mounted within a box or cabinet carried outside the cab and so situated that the engineer cannot have access thereto without stopping the locomotive. The contacts 1&6, 123 and 12% are included in a circuit connected in shunt of the winding of the valve holding magnet. Relay R is connected in the circuit of a generator G driven at a speed proportional to the speed of the locomotive, the relay and generator having such relative adjustment that the relay will become energized when the locomotive exceeds a predetermined speed only. Relay R is provided with an armature 122 adapted, when in its retracted position, to maintain a circuit from battery 100 closed through the windings of the valve holding magnet MV.

In describing the operation of our invention, we will proceed, first, with the operation of the track circuits and their associated apparatus including the wayside signals, as afiected by the presence of a car, and second, the operation of the cab circuit and its associated apparatus as affected by the conditions of the track circuits in the block sec tions. The condition of the track circuit and associated apparatus of a block section when its section and the next succeeding section are clear of traflic is as shown at B, Fig. 1. In this condition, the high resistance relays 2 1 30 and are held energized due to the difference in potential between the rails, the polarized, high resistance relay 25 being so connected that its armature 28 assumes the position shown when the rails are of the polarity indicated at 11 and 13". Upon the entrance of. a car into a block section, moving from left to'right of the observer, the circuits and apparatus of the section are brought into the condition as shown at A Fig. 1. although insulated from each other, form a metallic shunt of negligible resistance across the rails and 56 reducing the difference of potential between the terminals of the high resistance relays 2 1 and 30 sufliciently The trucks 12 and 12 of the car,

to cause them to become denergized and release their armatures 31 and 29*, respectively. The retraction of armature 29 opens the circuit of the semaphore motor M at contact 28", deenergizing the motor and permitting the semaphore 57 to rise to danger position, as shown. The retraction of armature 31 completes a circuit in the next preceding block section, not shown, through contact 41 its the pole changer 21" has not been operated the armature 28 of the polarized relay 25 remains in the position shown. Then the car passes the insulated joint I, sub stantially all of the current flowing through the trucks 12 and 12 traverses the windings of the current relay 23, by way of its connection with the rail 55 at 52 and 53 This large volume of current energizes the relay 23 causing it to attract its armature 32 which breaks connection with the contact 38 and makes connection with the contact 37 completing the circuit of the solenoid 20 as follows: battery 18, 40 32 87, 86, 35, through the windings of the solenoid 20 and back to battery 18*. The solenoid 20 thereupon draws in its core 19 switching the arms 15" and 4c of the pole changer into contact with the contacts 51 and 16, respectively. As the positive pole of track battery 17 is connected to contact 15 and the negative pole to contact 16 the polarity of the rails 55 and 56 is reversed, 2". 0., rail 55 is now connected to the negzn tive pole of the track battery by way of contact 16*, arm r, conductor 5, relay 22, 10* and track connection 11, while the rail 56 is connected to the positive pole of the track battery by way of contact 51 of the pole changer, arm 15 and track connection 11s the windings of'the polarized re lay 22 are included in the track supply circuit, just traced, the circuit in its winding is reversed causing its armature 33 to swing ever to the left and engage contact 34 partially completing a circuit for the solenoid 20 as follows: back contact 88 of relay 23, contact 42, a mature 31, 14 83 34 35, solenoid 20 battery 18', 10 to armature 32 It will be seen that the circuit just traced will be completed upon the de'e'nergization of relay 2?)and so will operate to maintain the solenoid 20'" energized and hold the track circuit in the reversed condition should the relay 23 be short circuited by the passage of the trucks of a following train over the insulated joint I, thus preventing a following or second train, entering the block before the first train has left it, from reversing the polarity of the rails and estab lishing a false clear signal. The reversal of the polarity of the rails, by the energization of the solenoid 20 causes the armature 28 of polarized relay 25 to move over to the right out of engagement with contact 27% effecting another break in the circuit of the semaphore motor M, hen the car moves out of the block A the shunt through its trucks is removed from across the rails which reduces the flow of current in the winding of relay 23 to a minimum, such current being only the amount that would leak across the roadway. As relay 23* is low wound this current is not sufficient to maintain it energized and so it releases its armature which upon retraction disengages with contact 37 and engages with contact 38. The removal of the shortcircuit from across the rails also causes a rise in potential between the rails whereupon the high resistance relay 2% takes sufiicient current to become energized and retract its armature 31. The rise in potential also causes the high resistance relay 30 to become energized which attracts its armature 29 into engagement with contact 26 partially completing the circuit of the semaphore motor M which, however, is maintained open at the break between armature 28 and contact 27* of the polarized relay so long as the polarity of the rails is reversed. The opening of the circuit of the solenoid 20 at contact 37 does not deenergize the solenoid inasmuch as the forward trucks of the car enter the next succeeding block B before the rear trucks leave the block A which causes the relay 24 to become deenergized maintaining the circuit of the solenoid 20- over the following path: battery 18*, tO 41 31 i9", 36, 35 20 and back to battery 18. As the relay 249 will remain deenergized so long as the car is in the block B the rails of the preceding block A will be held at the reversed polarity until the car leaves the block B whereupon the energization of the potential relay 24: will open the circuit of the solenoid 20, as last traced, permitting the arms 15 and P of the pole changer 21 to be retracted back into engagement with the contacts 16 and 3, respectively. This restoration of the pole changer to normal position again reverses the track supply circuit so that the rails assume their normal polarity with the rail 55 positive and rail 56 negative. This reversal of polarity causes the armature 28 of the polarized relay 25 to swing back over to the left into engagement with contact 27 thus completing the energizing circuit of the semaphore motor M which operating moves and holds the semaphore arm 57 down at clear indicating position. It will be seen that the function of the high resistance relay is to open the circuit of the semaphore motor when a car is in the block and that the function of the polarized, potential relay 25 is to maintain the circuit of the semaphore motor open so long as the polarity of the rails is reversed from that of normal or clear. It will also be seen that the presence of a car in a block section will maintain the rails of both it and the next preceding block at reversed polarity. The condition existing in two adjacent blocks, the succeeding block being occupied by a car, is shown at C and D, Figs. 1 and 2, respectively. In the occupied block D the solenoid of the pole changer is held energized through the armature of the low resistance relay 23 while the solenoid of the pole changer in the next preceding block G is held energized through the armature and contacts of the high resistance relay 24L of the occupied block D. In block D the circuit of the semaphore motor is maintained open at the contacts of both relays 30 and 25 due both to the drop in potential and the reversal of polarity, while in block C the circuit of the semaphore motor is maintained open at the contacts of relay 25 due to the reversal of polarity. The condition existing in two adiacent blocks upon the entrance of a car into the preceding block before the succeeding block is vacated is shown at E and F, Fig. 2. Here, the'deenergization of the high resistance relay 2& completes the circuit for the pole changer 21 through the armature of the polarized relay 22 and the armature and back contact of the current relay 23 which circuit is independent of the circuit controlled by the contacts of high resistance relay 24? of the next succeeding block. The circuit of the pole changer solenoid, as traced through the contacts of relay 24, is interrupted at contact 38, when the car passes the insulated joint I causing relay 23 to become energized, but another circuit for the solenoid 21 is immediately established through the contact 37 Thus the rails of the block E are maintained at the reversed or ofl normal polarity from the time the car enters the block until the time it leaves, the reason for which will be brought out in the description of the operation of the cab circuits and apparatus which follows.

The condition of the cab circuits as existing in the cab of a car when moving from left to right of the observer, at a caution, or less than caution speed and through a clear block section is shown in Fig. 3. In this condition, as before stated, the rails 55 and 56 (Fig. 3) are, respectively, positive and negative so that current will flow over the rails and through the trucks in the direction indicated by the arrows: This fiow of current together with the resistance of the rails between the points where the trucks l2 and 12' contact therewith, produces a difference of potential between the two trucks which would be of the polarity indicated on the drawing (Fig. As the trucks are insulated from each other, this difierence of potential causes a flow of current through the primary circuit of the cab as follows: truck 12, conductor 108, coil R, 103, relay R 104:, polarized relay PR, 105, and back by way of truck 12. This flow of current energizes both relays PR and R the relay PR being so connected in the circuit that upon the flow of current therein in the direction traced its armature 106 will be attracted into engagement with contact 127 as shown. The engagement of the ar mature 106 with contact 127 completes the circuit of relays R and R in series with the battery 18 as follows: battery 18, 117, R 118, 106, 127, R 11 and back to battery 18. The energization of R causes it to attract its armature 162 partially completing the circuit of relay R at .contact 115, while energization of relay R causes it to attract its armature 121 completing the circuit of the green lamp by way of armature 121, contact 133, 116, the green lamp, 113, battery 18, 117 and armature 121. Inasmuch as the car is proceeding at caution speed, the generator G does not generate current at sufficient potential to energize the high resistance relay R so that the armature 122 of said relay remaining in engagement with contact 135 maintains a closed circuit including the battery 100, recorder RC and valve holding magnet MV which may be traced as follows: from battery 100, through the magnet H1 of the recorder RC, conductor 1 10, 139, MV, 138, 137, 136, armature 122, contact 135 and back to battery 100. The circuit just traced is maintained, regardless of the condition of the track circuit, as long as the car is pro-' ceeding at caution speed, and no changes in the cab circuits will take place until the car has traveled a predetermined distance into the block and past the insulated joint I as indicated at D, Fig. 2. passes this point the polarity of the rails becomes reversed, in a manner before described, which reverses the flow of current in the primary circuit of the cab causing the armature 106 of the polarized relay PR to swing over into engagement with contact 126. This opens the circuit of relay R at contact 127, and closes the circuit of relay R in series with R over the following path: battery 18, 11, 115, 162, R 150, 120, 126, 106, 118, R 117 and back to battery 18. The armature 162 of relay B being slow acting does not disengage .its contact 115 during the short time interval between the interruption of the circuit of R and the completion of the circuit of R The relay R energizing, attracts its armature 119 completing a locking circuit thcrethrough from point 11 in shunt of the contact 11:3 so that when the armature 162 is retracted disengaging contact 115, the relay R is held energized over its locking circuit. The relay R is held energized in ser'es with R" over the circuit just traced Vhen the car and so maintains the circuit of the green lamp as before described. The engineer noting that the green lamp continues glowing after passing a predetermined distance into the block, increases the speed of the car to a maximum or any suitable degree above the caution speed. When the car passes over an insulated joint into the next succeeding block the relay R is momentarily deenergized, the period of denergization being equal only to the time required for the rear truck 12 to enter the block after the forward truck 12 has passed therein over the insulated joints. If the block thus entered into and the next succeeding block is clear, the polarity of the rails will be reversed to that of the rails in the block just vacated, that is the polarity will again be as indicated in the drawing (Fig. This change of polarity causes another reversal of current in the primary cab circuit which in turn causes the armature 106 of the cab polarized relay to again engage contact 127, interrupting the circuit of relay 1* and completing the energizing circuit of relays R and R in series. Relay R remaining energized maintains the circuit of the green lamp. The relay R denergizing permits its armature 119 to retract, opening, the locking circuit while the armature 160 does not fall back immediately as it is slow acting and so timed as to remain in engagement with its contact 129 for a definite time equal to the time required for the car to enter the block and pass the predetermined point at which the insulated joint 1 (Figs. 1 and 2) is situated. After the car passes a predetermined distance into the block the polarity of the rails is reversed in the manner before described, making the rail negative and rail 56 positive, which causes a reversal of current in the primary circuit of the cab whereupon the armature 106 of the polarized relay PR engages contact 126.

This operation of the polarized relay PR again completes the energizing circuit of relays R and R in series which circuit becomes locked as before. Relay R becoming again energized before the time limit of its slow acting armature160 expires, maintains the circuit of the valve holding magnet. Thus the cycle of operations of the cab circuit and apparatus is repeated for each block until the car enters a block in which the polarity of the rails is reversed from normal, that is the rail 55 negative and the rail 56 positive, which condition would exist when either the block just entered into or the next succeeding block is occupied. Under such condition, when the car passes over the insulated joints into a block in which this danger indicating condition exists there is no reversal of current in the primary cab circuit inasmuch as the corresponding rails of both the block vacated and the block entered are of the same polarity. However, when the car passes from one block into the other the relay R is momentarily deenergized as before which interrupts the locking circuit of relay R and as this circuit includes the circuit of relay R the latter relay becomes deenergized releasing its armature 121 and completing the circuit of the red lamp as follows: battery 18, 117, 121, 11%, the red lamp, 113 and back to battery 18. Under such circumstances the condition of the track circuits of the block in which the car is now running is as indicated at E (Fig. 2), which condition will maintain as long as the car is in the block, by virtue of the solenoid 21 being closed through the contact of polarized relay 22 and contact of high resistance relay 2% until the car has passed the predetermined distance into the bloclt, and thereafter by the closure of the solenoid circuit through the front contact of low resistance relay 23 until the block is vacated. As the polarity of the rails is not reversed during the passage of the car through this block the armature 106 of the cab polarized relay PR remains in engagement with contact 126 so that the relay R remains de'energized and the red lamp continues to glow. The engineer noting this reduces the speed of the car to caution speed and the generator Gr, slowing down proportionately, causes the relay R to release its armature 122 which upon retraction engages the contact 135 completing an independent holding circuit from the valve holding magnet MV as before de scribed. hen the predetermined time for which the slow acting armature 160 of relay R is set as expired, this armature moves out of engagement with its contact 129 which, however, does not affect the valve holding magnet as its circuit is now closed through contact 135 of relay R This condition of circuits maintains until the car enters a block in which the rails are at the normal polarity as indicated in the drawing (Fig. 3), whereupon the circuit of the polarized relay PR is reversed causing the armature 106 to swing over to the right and engage contact 127. This again energizes relays R and R relay R partially complating the energizing circuit of R and the relay R switching the green lamp into circuit, all in a manner as before described. The glowing of the green light indicates to the engineer that the block just entered and also the next succeeding block is clear; the engineer, however, must still proceed at caution speed until the car has moved the predetermined distance into the block where the insulated joint I is passed and the polarity of the track rails becomes reversed to that of normal. The armature of the polarized relay PR then swings over to the left into engagement with contact 126 and completes the energizing circuit of relay R in series with relay P this circuit becoming locked through the armature 119 of relay R as before described. Relay R upon energization also attracts its armature 160 into engagement with contact 129 so that the circuit of the valve holding magnet is again held closed independently of the contact of relay B so that the engineer can now increase the speed of the car without affecting the valve holding magnet or the recorder. It is to be noted here that should either the track circuit or the primary cab circuit fail, the relay R will become de'e'ncrgized, opening the circuit of R, which latter relay upon deenergization would cause the red lamp to be connected in circuit with its local battery 18, giving the danger signal. Should the engineer not heed this danger signal before the expiration of the time for which the slow acting armature 161 of R has been set and has not brought the car down. to the caution speed, the armature 161 disengaging its contact 125 will interrupt the circuit of the recorder and valve holding magnet. also, when the car enters a block in which the polarity of the rails is reversed to normal and the relays R and R become deenergized, the red lamp giving the danger signal, if the engineer does not heed the danger signal and bring the car down to the caution speed before the expiration of the time for which the slow acting armature 160 has been set, the armature 160 upon disengagement with contact 129 will interrupt the circuit of the recorder and valve holding magnet as the other path for this circuit would be open at the contact 135 of relay R \Vhen from any cause the circuit in which the recorder and valve holding magnet is included is.

opened, the magnet H1 of the recorder RC deenergizing releases the recording needle 1-12 which under tension of a suitable retractile spring is retracted so as to punch a hole in the moving dial or tape Hat, while the valve holding magnet MV becoming deenergized permits its core to retract under the force of gravity or other suitable retracting means, opening the valve of the train line and bringing the bridging con.- tact 152 into engagement with contacts 123 and 12l which connection forms a shunt circuit across the terminals of the valve holding magnet which shunt circuit may be traced as follows: 138, 121, 152, 123, 146, HS and 139. This opening of the train-line valve will cause the breaks of the car or train to be applied in a well known manner and bring the car or train to a stop, the generator G slowing down proportionately and finally stopping with the car, relay R releasing its armature and completing the circuit of the recorder and valve holding magnet through eonta ct Upon the completion of this circuit the recorder magnet Ml becomes again energized, attracting the recording needle 142, but the valve holding magnet cannot become energized again until the shunt across its terminal is removed by operating the normally closed spring switch H8. To effect this removal of the shunt the engineer must, preferably, get out of the cab, as before described. Upon removal of the shunt the valve holding magnet again attracts its core, closing the valve of the train line and opening the shunt circuit at contacts 1i and 12d and the engineer is enabled to again proceed at caution speed.

In Fig. 4 we have shown a modification of Fig. 3, in which a contact 163 is added to the polarized relay PR and connected to the point 117 in the circuit of relay R. The efiect of this is to put a jumper across the terminals of B when the armature 106 is in its right hand position, and the primary con dition of the track thus causes R to be demagnetized due to being short-circuited. This condition holds until the train gets past the insulated joint I. A brake in the relays or in the primary circuit would of course put it on open circuit also. The red light lights in both cases. When 106 is in contact with 126, the green light burns, this condition holding while the train is passing over the insulated oint T to the end 01": the

block when the red light burns until the re-' versal of current in the track.

The relay R might also be connected between the contact 126 and the armature 120, with the same relay. The idea is to give this relay an absence of potential it there is no reversal of current when the car is entering a. block.

It will of course be evident upon reading this specification, and considering the cir cuits. that divers changes can be made in details without departing from the scope and purview of the invention. The foregoing modification is only one of many which will occur to the engineer skilled in this art. Ive wish it distinctly understood therefore that we have described all the detail apparatus and circuits herein for the purposes of definition only and not of limitation. We contemplate and consider as part of our invention, all modifications and changes which fairly fall within the scope of the appended claims.

Having thus described our invention what we claim and desire to secure by Letters Patent is:

1. In a railway signaling system having a track divided into block sections, comprising a source of current bridged across the rails of the section, a high resistance relay also raidged across said rails, and a low resistance relay bridged over a breakin one of the rails of the section, said relays acting jointly to vary the connection of said source of current with the rails, together with means connected to a vehicle adapted to travel over the railway track, for controlling the potentials across said relays and the current flow therethrough, and signaling apparatus on the vehicle responsive to said changes in connection of the source of current with the rails.

2. In a railway signaling system having a track divided into block sections, a source of current bridged across the rails, a high re sistance relay also bridged across the rails, a low resistance relay bridged around a break in one or the rails of the section, and a pole changer jointly controlled by both of said relays, with signals controlled through said pole changer, together with a polarized signaling means carried upon and moving with a. vehicle traveling over the railway track.

3. In a railway signaling system, track rails, a source of current connected to said rails at points separated longitudinally from each other by a predetermined distance and a signal connected through contacts longitudinally separated on the rails and respon sive to thedrop in potential between said contacts.

4t. In a 'ailway signaling system, sectional rails, a source of potential bridged thereacross at points longitudinally separated from each other, a vehicle having means for effecting electrical contact with both rails at points separated from each other, a signal on the vehicle energized by the drop in potential between said points of contact and a circuit for said signal extending between said contacting devices, with means to change the circuit of the source of potential so as to bring about operating changes in the circuit of the signal.

5. In an electrical railway signaling sys tem, a source of current, means to control the same for signaling purposes, connections from said source to longitudinally separated points on the track rails, a vehicle, a signal, and means to efiect connections from the vehicle to the rails at intermediate but separated points on both rails having the same polarity but at diiferent potentials.

6. A railway signaling system for a track divided into block sections, comprising a source of current bridged across the rail sections from one end of one rail to the other end of the opposite rail, a vehicle having means for bridging both rails at longitudinally separated points, a signal operable in shunt of said rails between said points, and circuit connections including said signal and extending between said separate bridging means, whereby the signal may be exposed to a difference in potential due to the drop in the rails.

7 A railway signaling system for a track divided into block sections, comprising a source of current connected across the section rails from one end of one side rail to the opposite end of the opposite side rail, a pole changer controlling the polarity of said source with respect to the rails, controlling means for said pole changer responsive to the passage of vehicles over the rails, a vehicle having longitudinally separated pairs of wheels bridging both rails, a signal on said vehicle, and a circuit for for said signal extending between said pairs of wheels, whereby a drop in potential between the points of contact of the respective pairs of wheels, around the resistance of the intermediate portion of both rails will be produced across the terminals of said signal, said signal being energized by said drop in potential and controlled through the agency of said pole changer.

8. A railway signaling system for a track divided into block sections, comprising a source of current bridged across at the rails of each section at points longitudinally separated from each other, alow resistance relay bridged around a break in one of said rails between the points of connection of the source, a pole changer for the source controlled by said relay, a vehicle having circuit connections with the rails at separated points, and polarized signaling means on the vehicle working on the drop in potential between said separated points.

9. A railway signaling system for a track divided into block sections, comprising means electrically dividing the rails of each section, a vehicle, a cautionary signal on said vehicle, a relay controlling the same, and a circuit for said relay terminating in separated rail contacts, together with means acting normally when the line is clear, to produce a momentary reversal of the operation of said relay when the vehicle passes the division in the rail section, whereby the driver of the vehicle will receive a safety signal automatically for each section.

10. In an electrical signaling system for railways divided into block sections, the combination of the following instrumentalities: a source of current connected across the rails of each block from the rail on one side thereof to the rail on the other side thereof, a pole changer for said source for each block, a high resistance relay connected across the rails of each'block and adapted to control the pole changer of the preceding block, vehicles each adapted to short-circuit said relay upon entering its block and to complete a circuit from said source through the rails, and signals on said vehicles controlled by said relay responsive to change in polarity of said current.

11. In an electrical signaling system for railways divided into block sections, the combination of the following instrumentalities: a source of current connected across the sectional track rails from a point on one rail to a point longitudinally separated therefrom on the other rail, one rail of each block being divided intermediate of said points, a low resistance relay bridged around the break in said rail, a pole changer for the source controlled by said relay, a vehicle adapted to short-circuit the rails in passing through the block, and to energize said relay when it passes the said break, and signals on the vehicle responsive to change in polarity of current derived from the rails.

1:2. In an electrical signaling system for railways divided into block sections, the combination of the following instruinentalities: a source of current connected across the sectional track rails between points longitudinally separated on the opposite rails, one rail of each block being divided intermediate of said points, a low resistance relay bridged around the break in said rail, a pole changer for the source controlled by said relay, a vchicle adapted to short-circuit the rails in passing through the block, and to energize said relay when it passes the said break, and signals on the vehicle responsive to change in polarity of current derived from the rails, together with means actuated by a vehicle entering each block to maintain the altered condition of polarity in the preceding block until the rail. break in said vehicle occupied block is passed.

13. In an electrical railway signaling sys tem, track rails and a source of current therefor, a vehicle deriving current from points longitudinally separated on said rails due to drop in potential between said points, a relay on the vehicle responsive to said current, a cautionary signal and a danger signal on said vehicle controlled by said relay, means for stopping said vehicle, and speed controlled means controlling said stopping means ointly with said relay.

14. In an electrical railway signaling system, sectional rails and a source of current connected thereto, a vehicle deriving cur rent from the rails, a relay on said vehicle responsive to variations in said current, a danger signal on said vehicle controlled by said relay, a braking system for said vehicle, retarded means for operating said braking system, and speed controlled means adapted to jointly control said braking system when the retarded means are afiected by abnormal conditions, whereby slow cautionary running after exhibition of a danger signal may proceed within predetermined limits as defined by the retardation referred to, but faster running after a danger signal will result in stopping the vehicle.

15. In an electrical railway signaling sys tem, track rails and a source of current, a vehicle with track contacts at points separated longitudinally of the track and a circuit connected therefrom to a polarized relay, means for reversing the track current under abnormal conditions of danger, a danger signal and a cautionary signal on the vehicle both controlled by said relay, stopping means for the vehicle, a n'iagnet for holding said stopping means against operation, acircuit for said magnet normally closed, contacts in said circuit adapted to be opened by any reversal of current on the rails after a predetermined interval long enough to permit passage through the block under normal conditions, and other contacts in said circuit normally closed and adapted to be opened automatically when the vehicle exceeds a predetermined cautionary speed, whereby if the vehicle driver disre gards or disobeys a signal due to abnormal conditions, the vehicle will be automatically braked and stopped.

16. In an electrical railway signaling system, block sections each having a source of current bridged across it diagonally from one end of the rail to the end of another rail and a break in continuity in the middle of one rail, a high resistance relay bridged across the incoming end of the block, a low resistance relay bridged around the break in the one rail, a pair of relays, one non-polarized and one polarized jointly controlling the operating circuit of a wayside signal, a vehicle having separated wheel pairs contacting with the rails at such a distance apart longitudinally of the track as to permit of a drop in potential between them, a polarized relay and a non-polarized relay on the vehicle connected between the wheel pairs and responsive to changes in the current due to the drop in potential, a local circuit relay controlled by said polarized relay, a pair of lamp signals, one cautionary and one danger, controlled by back and front cont-acts respectively of said local relay, a pair of slow acting relays connected respectively to opposite contacts of the polarized relay and adapted to be interchangeably brought into circuit with the series relay according to the direction of current through the polarized relay, a speed control relay energized by current varying in proportion to the speed of the vehicle, and stopping means for the vehicle, including a magnet normally energized to maintain said stopping means inoperative, and a circuit for said magnet including a source of current on the vehicle and ointly controlled by said speed actuated relay, by the main nonpolarized relay responsive to track current, and by one of the slow acting relays under the control of the polarized relay, whereby normal reversal of current due to passage of the vehicle through a block will be signaled to the driver and the slow acting re lays maintained in operation and the stopping means maintained inoperative, but in the event of failure of the track source of current, the stopping means will be energized by deenergization of the main vehicle non-polarized relay, and in the event of reversal of current due to a vehicle in the next block which is just being entered, the stopping means will be actuated by the speed relay unless the driver slows down in response to the danger signal within the limit determined by the retarding devices of the slow acting relays.

17. In an electrical railway signaling system, a track source of energy and a vehicle carrying a time-controlled relay responsive thereto, a generator on the vehicle with means to vary its output proportionately to the speed of the vehicle, a relay controlled by said generator, and means for reducing the speed of the vehicle, controlled by said relays jointly, together with means for recording the time of operation of said speed reducing means.

In testimony whereof we atfiX our signatures in presence of two witnesses.

ALTON ALVIN ARMSTRONG.

GEORGE MASON RIVES. Witnesses:

GEO. W. BRIGHT,

S. E. W001).

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

